Though the numbers reported by Coursera (and also its competitor Udacity, which has more than 739,000 registered users in 203 countries) are impressive, they don’t represent the amount of learning actually taking place. Coursera co-founder Andrew Ng explained in an email interview that the number of active students is significantly lower because many registrations are for courses that have not yet begun and many sign up but don’t end up following through with the coursework. So are students interested in free online classes? Yes, but time will tell whether or not the registered students actually stick with the program.